1. Field of the Invention
The present invention relates to garbage collectors. More specifically, the present invention relates to a method and an apparatus for facilitating concurrent garbage collection.
2. Related Art
As object-oriented programming languages become more widely used, computer systems are being designed to manipulate objects more efficiently. One of the toughest challenges in efficiently manipulating objects is garbage collection. Non-concurrent, or “stop the world,” garbage collectors, which are in common use today, suffer from the problem that the entire application stops responding while a garbage-collection operation is in progress.
In contrast, concurrent garbage collectors can reclaim heap memory while the main application program (“mutator”) threads continue to execute. However, concurrent garbage collectors suffer from difficult synchronization problems. For example, the garbage collector must not be confused by the concurrent heap mutations and accidentally reclaim live data. These concurrency problems can be solved by using “garbage-collection (GC) barriers,” snippets of code that are executed by the mutators to ensure correctness of the garbage-collection operation. Typically, these GC barriers have a substantial cost in terms of performance and code size.
Hence, what is needed is a method and an apparatus for performing concurrent garbage collection without the problems listed above.